Normally, soft cigarette packets have a substantially parallelepipedal shape and consist of a first, complete inner wrap made of paper or metallised paper (foil), placed right around a group of cigarettes, also parallelepipedal in shape, and a second, outer wrap or label.
The second wrap is made from a length of wrapping material, usually paper, having two longitudinal edges and placed partly around the first wrap in such a way as to leave the top face of the latter free, to form the front, the rear and the two sides of the packet, and is also folded at the bottom of the first, inner wrap to form the bottom of the packet.
Once the second wrap or label has been folded around the first wrap, the label presents a free longitudinal edge extending along a defined perimetric portion transversal to the packet and adjacent to its top face, made of foil.
Normally, there is a revenue stamp applied in such a way as to straddle the top of the inner wrap, with its two ends glued at the top edge of the label.
The surface of the label is designed to be visible and is usually printed with decorative patterns and logos, forming a distinctive coloured graphical design, identifying the brand and the organoleptic properties of the cigarettes inside the packet.
Lastly, cigarette packets of this type are usually also wrapped and sealed with a protective overwrap made from transparent plastic film, for example, polypropylene, equipped with a tear strip designed to enable the overwrap to be easily torn in order to gain access to the outer wrap to open the packets.
The packing machines used to make the soft packets described above essentially comprise a packing line along which the preformed groups of cigarettes are fed to a packing station where a corresponding length of paper or metallised paper is folded and wrapped around each group of cigarettes to form the inner wrap. Next, each group of cigarettes enclosed by the first wrap is fed to a second packing line where a corresponding label is folded around the first wrap enclosing the group of cigarettes. When the packing operations have been completed, and the revenue stamp has been applied, the soft packets are usually fed to another machine which wraps and seals each single packet with the protective overwrap made of transparent plastic film.
Soft cigarette packets consisting of a single wrap are also known. The single wrap presents a printed section with a well-defined coloured graphical design constituting the label and designed to wrap the four lateral surfaces and one bottom of a group of cigarettes, and a second section having the appearance of metal foil designed to cover the top of the cigarette group. Packets of this kind have obvious economic advantages not only because they save wrapping material but also because the packing machines used to make them are much simpler than the conventional machine described above.
Further, U.S. Pat. No. 4,508,218 discloses a soft packet consisting of a single, one-piece blank, also presenting a first printed section constituting the label and designed to wrap the four lateral surfaces and one bottom of a group of cigarettes, and a second section having the appearance of metal foil and designed to cover the top end of the cigarette group.
At the line dividing the first section from the second, and along its full length, the blank has a Z-fold made by folding by 180° over each other two longitudinal portions of the blank at said dividing line and placing them over one another to form a reinforced portion along the dividing line itself. Once the blank made in this way is folded and wrapped around the cigarette group, the reinforced portion is located at and adjacent to the top of the packet right around its transversal perimeter. This type of Z-fold, besides strengthening the packet, also simulates the presence of an inner wrap and gives the packet the appearance of a traditional soft packet with two wraps.
Obviously, the blank of wrapping material used to make this type of packet must be considerably wider than a blank that does not have a Z-fold of the this kind. This means that a considerable amount of additional material is required, thus significantly increasing production costs.